UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 Sixth Avenue, Suite 900 Seattle, Washington 98101-3140

OFFICE OF THE REGIONAL ADMINISTRATOR 

### DEC082011

The Honorable C. L."Butch" Otter Governor of the State of Idaho Post Office Box 83720 Boise, Idaho 83720

Dear Governor Otter:

Thank you for your recommendations dated March 9, 2009 on air quality designations for the revised 2008 National Ambient Air Quality Standards for ozone throughout Idaho. I appreciate the information Idaho shared with the U.S. Environmental Protection Agency as we move forward to improve ozone air quality. This letter is to notify you of the EPA's preliminary response to Idaho's recommendations and to inform you of our approach for completing the designations for the revised ozone standards.

On March 12, 2008, the EPA revised its national ambient air quality standards for ground-level ozone to provide increased protection of public health and the environment. The EPA lowered the primary 8-hour ozone standard from 0.08 parts per million (ppm) to 0.075 ppm to protect against health effects associated with ozone exposure, including a range of serious respiratory illnesses and increased premature death from heart or lung disease. The EPA revised the secondary 8-hour ozone standard, making it identical to the primary standard, to protect against welfare effects, including impacts on sensitive vegetation and forested ecosystems.

History shows us that better health and cleaner air go hand-in-hand with economic growth. Working closely with the states and tribes, the EPA is implementing the standards using a common sense approach that improves air quality and minimizes the burden on state and local governments. As part of this routine process, EPA is working with the states to identify areas in the country that meet the standards and those that need to take steps to reduce ozone pollution. Within one year after a new or revised air quality standard is established, the Clean Air Act requires the Governor of each state to submit to the EPA a list of all areas in the state, with recommendations for whether each area meets the standard.

As a first step in implementing the 2008 ozone standards, the EPA asked states to submit their designation recommendations, including appropriate area boundaries, by March 12, 2009. In September 2009, the EPA announced it was reconsidering the 2008 ozone standards. The EPA later took steps to delay the designation process for the 2008 ozone standards pending outcome of the reconsideration. However, in September 2011, the Office of Management and Budget returned to EPA the draft final rule addressing the reconsideration of the 2008 ozone standards. On September 22, 2011, the EPA restarted the implementation effort by issuing a memorandum to clarify for state and local agencies the status of the 2008 ozone standards and to outline plans for moving forward to implement them. The EPAindicated that it would proceed with initial area designations for the 2008 standards, and planned to use

the recommendations states made in 2009 as updated by the most current, certified air quality data from 2008-2010. While the EPA did not request that states submit updated designation recommendations, the EPA provided the opportunity for states to do so.

As required by the Clean Air Act, the EPA will designate an area as nonattaimnent if it is violating the 2008 ozone standards or contributing to a violation of the standards in a nearby area. Consistent with designations for previous ozone standards, the EPA intends to designate an area as unclassifiable/attainment if there are certified, quality-assured air quality monitoring data showing the area is meeting the ozone standards or there are no monitoring data for the area, and the EPA has not made a determination that the area is contributing to a violation in a nearby area.

After considering Idaho's March 9, 2009 ozone designation recommendations and other relevant technical information, including 2008-2010 air quality data, the EPA intends to designate the entire state of Idaho as unclassifiable/attainment.

If Idaho has additional information that you would like the EPA to consider, please submit it to us by February 29, 2012. The EPA will also make its preliminary designation decisions and supporting documentation available to the general public for review and comment. We will be announcing a 30-day public comment period shortly in the Federal Register. After considering additional information we receive, the EPA plans to promulgate final ozone designations in spring of 2012.

The EPA is committed to working with the states and tribes to share the responsibility of reducing ozone air pollution. Current and upcoming federal standards and safeguards, including pollution reduction rules for power plants, vehicles and fuels, will assure steady progress to reduce ozone-forming pollution and will protect public health in communities across the country. We look forward to a continued dialogue with you and your staff as we work together to implement the 2008 ozone standards. Should you have any questions, please do not hesitate to contact me, or have your staff contact Claudia Vaupel at (206) 553-6121.

Sincerely,

Dennis J. McLerran Regional Administrator

cc: Toni Hardesty, Administrator Idaho Department of Environmental Quality Martin Bauer, Administrator Air Quality Division, Idaho Department of Environmental Quality Gina McCarthy, Assistant Administrator Air and Radiation, EPA Steve D. Page, Director Office of Air Quality Planning and Standards, EPA